The overall objectives of the project are to continue to delineate and develop methods for the study of vitamin B12 and folate absorption, transport, delivery, storage, utilization and excretion, and to continue to delineate the factors involved in the above processes; to further investigate the metabolism and function of binders for vitamin B12 and folate; to further develop the therapeutic use of lithium in hematology, the understanding of effects of ascorbate on vitamin B12 metabolism, and to conduct other studies which arise as an offshoot of our vitamin B12 and folate investigations. During the current year, attention will be particularly focused on studies of vitamin B12 and folate binders to further identify and evaluate changes characteristic of various clinical conditions, and develop these as diagnostic aids and therapeutic markers. As a necessary prerequisite to understanding the function of folate binders, they will be further characterized using various chromatographic techniques, electrophoresis, and functional studies. Efforts will be directed towards the improvement and streamlining of routine folate and B12 assays, and assays for their binders. Previously unidentified target groups for folate deficiency will be sought using novel techniques recently developed in our laboratory.